The present invention relates to a disk array device and a technique for controlling the same and, more particularly, to a technique effectively applied to a controlling method of replication of a storage unit system that can be connected to a plurality of different kinds of networks.
The inventors of the present invention have examined a conventional disk array device and a technique for controlling it and consequently understood as follows.
Recently, there has been a rapid increase in quantity of data to be handled in a computer system. To efficiently utilize and manage such vast data, there has been developed a technique which connects a plurality of disk array devices (hereinafter “storage unit systems”) and an information processing apparatus to each other through a dedicated network (Storage Area Network, which is hereinafter abbreviated as “SAN”) so that high-speed and vast data access to the storage unit systems can be realized. In order to realize high-speed data transfer by connecting the storage unit systems and the information processing apparatus to each other, generally the network is built up using a communication instrument that complies with a fiber channel protocol.
Meanwhile, there has been developed a network system referred to as a network attached storage (NAS), which connects a plurality of storage unit systems and an information processing apparatus to each other through a network that uses a transmission control protocol/Internet protocol (TCP/IP) so that the storage unit systems can be accessed at a file level. In the NAS, a device having a file system function is connected to the storage unit system, so that it is possible for the information processing apparatus to gain access at a file level. See Japanese Patent Laid-open No. 2002-351703.